Exhaust aftertreatment systems are used to receive and treat exhaust gas generated by internal combustion (IC) engines. Conventional exhaust gas aftertreatment systems include any of several different components to reduce the levels of harmful exhaust emissions present in exhaust gas. For example, certain exhaust aftertreatment systems for diesel-powered IC engines include a selective catalytic reduction (SCR) catalyst to convert NOx (NO and the NO2 in some fraction) into harmless nitrogen gas (N2) and water vapor (H2O) in the presence of ammonia (NH3).
The ammonia used by the SCR system for reducing the exhaust gas is generally provided in the form of a liquid exhaust reductant. The liquid exhaust reductant is stored in an exhaust reductant tank and communicated into the SCR system from the tank via a pump. Pumps used aftertreatment should preferable have a small form factor, be robust and be able to resist corrosion from the exhaust reductant.